1. Field of the Invention
This invention relates to electrical rectifying circuits which may be useful in, for example, AC measurement systems or employable as AC to DC voltage converters or as signal dectectors.
2. Discussion of Prior Art
Known methods of signal detection employ at least one semi-conductor junction diode, usually a silicon diode. One disadvantage, which the silicon diode has, is its negligible response below the cut-in voltage. (This is approximated 0.6V at 20.degree. C.). Consequently, its performance as a rectifier or detector is grossly non-linear for small signal voltages. Diode sensitivity may be increased by the known method of incorporating it within the feedback loop of an operational amplifier, which effectively reduces the cut-in voltage almost to zero. However, the linearity of such a circuit as an AC to DC converter suffers at low signal levels due to distortion.